1. Field of the Invention
The present invention relates to a dust collection system, and in particular, to an arrangement on top of a hopper for preventing excessive dust from escaping into the atmosphere during loading of the hopper.
2. Description of Related Art
Although the present invention is primarily intended to minimize dust during the loading of dockside mobile hoppers with clinker using ship cranes, the application has widespread application. For example, the present invention could be utilized in grain bins, and in any other application in which particulate matter generates unacceptable levels of dust during loading thereof.
Many states have environmental regulations controlling and limiting the generation of dust. See, e.g., Chapter 403 of Title 62 of the Florida Statutes and the rules promulgated thereunder in the Florida Administrative Code. See, in particular, Section 62-204, F.A.C.
Prior to the present invention, several efforts had been made to control dust. For example, U.S. Pat. No. 4,324,524 discloses a dust retention device for containing dust arising from the handling of particulate material. The '524 patent discloses a plurality of shutters 6, 7, 8, that are suspended from rods 9. However, the shutters 6, 7, 8 are not overlapping, and there is an opening between the shutters through which dust can escape. Furthermore, the shutters are able to pivot or rotate about the rods 9, thus enabling the openings to become rather significant. As a result, large quantities of dust may be emitted through these openings.
U.S. Pat. No. 4,699,187 discloses another dust control system. The system disclosed in '187 patent utilizes large shield plates 24, 24' to trap dust therebeneath. The system disclosed in the '187 patent does not utilize a plurality of openings extending along the area underneath the plates 24, 24'. Instead, the disclosed system utilizes collectors 20, 20' at each end of the system. In addition, the '187 system includes a fabric filter 22 over the intake areas, which would limit the ability of the system to collect and remove dust.
U.S. Pat. No. 3,885,606 discloses an apparatus for loading fine granular and pulverized loose solids. The disclosed apparatus seems more concerned with breaking up the material and removing air from it, than for containing dust.
Accordingly, prior to the present invention, there existed a need in the art for an economical and effective system for minimizing the amount of dust generated when loose particulate material, such as cement clinker, is loaded into a hopper.